Blood vessels and other physiological structures can fail to perform their proper function. An example, in the case where opposing valve leaflets within a vein do not touch each other, blood flow within the vein is not predominately restricted to one direction towards the heart. This condition is called venous reflux, and it causes elevated localized blood pressure within the vein. Elevated localized blood pressure is subsequently transferred to the surrounding tissue and skin. Furthermore, failure of a valve in a vein causes a cascading reaction of successive failure of valves along the vein. In order to standardize the reporting and treatment of the diverse manifestations of chronic venous disorders, a comprehensive clinical-etiology-anatomy-pathophysiology (CEAP) classification system has been developed to allow uniform diagnosis. The CEAP classification is commonly used to describe the level of patient symptoms, which increase in severity from spider veins, to varicose veins, to swelling (edema), to skin changes (bluish staining, lipodermatosclerosis), to previously healed ulcer, finally to active ulceration which is regarded most severely. Chronic venous insufficiency is a term often used to describe the more severe symptoms of chronic peripheral venous disease.
The human lower extremity veins consist of three systems: the superficial venous system, the deep venous system, and the perforating venous system, which connects the superficial and the deep systems. The superficial system includes the great saphenous vein (GSV) and the small saphenous vein (SSV), among others. The deep venous system includes the anterior and posterior tibial veins, which unite to form the popliteal vein that in turn becomes the femoral vein when joined by the small saphenous vein.
An early technique for treatment of venous reflux is surgical stripping of the vein. This is done by passing a flexible rod or cable through the vein, and then either pulling back with an acorn-shaped head to help sever the vessel side-branches or pulling the vein out through the lumen of the vein (invaginate stripping). The stripping method typically requires general anesthesia and usually requires a prolonged healing period of up to two weeks due to heavy bruising, pain and tenderness.
Sclerotherapy is a treatment where a caustic solution (e.g., polidocanol, sodium tetradecyl sulfate, sodium morruate, isotonic saline) is injected into the vein causing irritation of the vein wall to such a degree that the vein wall is damaged and the vein lumen is filled with thrombosis (clot). Sclerotherapy can be effective, but it often requires repeat treatments and it has been reported to cause a higher rate of nearby deep vein thrombosis, as well as staining/matting of nearby skin. Larger veins are often treated with a foamed mixture of sclerosant with air or Carbon Dioxide. Sclerotherapy does not generally require any anesthesia, although there can be some tolerable pain upon injection of the solution.
Endovenous thermal ablation is a recent technique where heat is applied within the vein to cause the vein wall to permanently shrink to the point the vein lumen is occluded (usually by a residual core of blood thrombus). Radiofrequency ablation was first reported, followed by laser ablation and then steam ablation. Endovenous ablation is typically done with local anesthesia in an outpatient or physician office setting.